Screw driver



Nov. 22, 1932. H. B. CUR-ns ET AL SCREW DRIVER Filed Deo. 26, 1931 2 Sheets-Sheet MII Nov. 22, 1932. HA la CURTIS ET AL SCREW DRIVER Filed Deo. 26, 1931 2 Sheets-Sheet' 2 named Nev. a, :aaa

UNITED STATES PATENT 'orf-'Ica maar n. conm or mm'rmeron, um anrnun n. marine.. or namemon'r, oonnc'rrou'r, sssrcnoas ro run animaron mnwm nmncruamo con. ronnon, or animaron, oonnnc'rrcu'r, a oonroaarxon or oomo'rrcor SCREW DRIVER Application lied December 86, 1831. Serial No. 588,298.

This invention relates to new and useful improvements in screw drivers, and has for an object the providin of a screw drivel, including a detachable andle and blade-construction, whereby in the event of the blade bein broken, it may be removed from the bangle and a new blade substituted.

Another object is to provide a screw driver as stated, and including a handle having an insert and a blade having a portion received by the insert and co-operating therewith in a manner to permit removal of the blade from the handle, but to effectively prevent relative turning movement between the blade and handle.

A further object is to provide a screw driver including a blade and a handle, the handle being molded, preferably although not necessarily, of an insulating material, and having a metallic insert molded therein to receive a ortion of the blade to removably secure the glade and handle together and against relative turnin movement.

Other objects and advantages will become apparent from a consideration of the following detailed description taken connection with the accom anying drawmgs wherein preferred embodiments of the inventlon are shown. However, it will be understood that the invention is not limited to the details disclosed, but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims to which claims reference should be had for a definition of the invention.

In the drawings: I

Fig. 1 is a side elevational view of a complete screw driver in accordance with the invention;

Fig. 2 is an end view of thesame, the view being taken looking from the bit end of the b ade;

Fig. 3 is a view substantially at right angles to Fig. 1 an insert and the blade being shown in elevation and the handle being shown in longitudinal section, the handle being a section substantially along the line 3-3 of Fig. 2;

Fig. 4 is an end view showing the insert and blade, the handle being omitted;

Fig. 5 is a sectional view through the insert substantially along the -line 5 5 of Fig. 4 the shank endi of the bit being shown in e evation; v

Fig. 6 is a view taken at right angles to i and substantially along the line 6.-6 of ii modied form of insert, the handle omitted;

. Fig. 8 is a view partly in section and partly in elevation, the handle being indicated by broken lines, and the view bein taken substantially along the line 8-8 og Fig. 7;

Fig. 9 is a sectional view taken substantially along the line 9-9 of Fig. 7, the shank end of the bit being shown in elevation;

Fi 10 is an end view of yet another modified orm of insert;

Fig. 11 is a side elevational view of the insert of Fi 10, the handle being indicated by broken ines;

Fig. 12 is a sectional view substantially along the line 12-12 of Fig. 10, the shank of the bit being shown in elevation;

Fig. 13 is a view partly in elevation and partly in section, and showing a further modified construction;

- Fig. 14 is a sectional view substantially along the line 14-14 of Fig. 13;

Fig. 15 is a view partly in section and partly in elevation, and showingyet a further modified construction;

Fig. 16 is an end elevational view of the insert of Fig. 15; and

Fig. 17 is a side elevational view of the insert of Fig. 15, a portion of the shank of the bit being shown.

Referring in detail to the drawings, and first particularly to Figs. 1 through 6 thereof, the improved screw driver is shown as ineing cluding a handle 20, an insert 21 in the han` dle, and a blade 22 having the end portion 23 of its shank received in the insert 21. The insert 21 is preferably formed of iron, steel or the like, and its intermediate portion 24 which extends for the greater ortion of its length is here disclosed as cy indrical and roughened or knurled on its outer surface.

Toward one of its ends the insert is pro- 7 is an end view showing a slightly.

2. Losanna vided with a slightly enlarged portion 25, and outwardly of said portion 25 is again enlarged as at 26 and the portion 26 is formed with fiat sides for the reception of a wrench or other turning tool, and is here shown as hexagonal. The insert is provided with a central longitudinally extending recess or larged at sided end 26 thereof and extending for substantially the entire length of the insert and terminatin in the shoulders 28. Through its inner en the insert is kerfed or transversely slotted as at 29, and this kerf or slotfforms a continuation of the inner end of the recess 27, and extending from side to side of the insert forms a pair of tongues or iin ers 30 at the inner end thereof.

rom Fig. 5 it will be clear that the shoulders 28 are formed at the juncture of the recess 27 and the transverse slot or kerf 29, and

that the shoulders result from the fact that the diameter of the recess is greater than the Width of the slot or kerf. Somewhat inwardly of its slotted end the insert is provided with a shoulder 31, and resting on this shoulder and disposed about the slotted end of the insert in a manner to embrace the extensions or fingers 30 and so prevent spreading of them, is an iron or other metal collar or band 32. Y

Handle 20 is of hardened moldable material and has the insert 21 molded therein. It is preferred that the handle he formed of electrlcal insulating material, although 1t will be understood that this is not essential. When molding the handle the intermediate exteriorly roughened portion 24 of the insert as well as the inner end portion thereof and the collar or'band 32 are all molded in the handle. If desired, a metal washer 33 may be disposed on a shoulder 34 formed at the juncture of the portions 25 and 26 of the 1nsert, and this washer will in the finished construction abut the inner end of the handle as shown in Figs. 1 and 3. It will of course be understood that Ain lieu of the separate washer 33 as shown in Fig. 3, a flange or washer may be formed integral with the flat sided or nut portion 26 of the insert.

The screw driver blade generally designated 22 includes a bit 35 at one end of its shank and the other end of its shank is reduced on opposite sides as at 36. The sides or portions 36 are shown as iat and these portions taper somewhat toward the end of the shank. In practice this taper is very slight and is exaggerated in the drawing in order that an inspection of the drawing will make the taper apparent. It is sufficient to cause the sides of the tapered portion to bind on the inner walls of the slot 29 and retain the blade in the handle.

As before suggested the insert 21 is placed in a mold and the handle 2() is molded about the insert. After the material of the handle assage 27 opening through the enhardens the insert will be very tightly held in the handle and will not be turnable relative tothe molded portion and in fact the insert w1ll form part of the handle. Owing to the fact'that the exterior surface of the portlon 24 of the insert has been roughened or knurled the parts ,will be inseparable.

After the insert has been molded into the handle and the blade formed with the tapered end portion as above described, the blade may be easily inserted into the handle to form a complete screw driver. The blade is of course inserted into the recess 27 of the insert I21 and the tapered end portion of the blade is disposed in the relatively narrow kerf or slot in the inner end of the insert. Owing to .the taper of its surfaces 36 a wedging actlon will take place between the inner end portlon of the blade and the inner surfaces of the extensions or fingers 30 and the blade w1ll thus be secured in the handle ready for use.

The wedging action which takes place between th e blade and the insert is such that the blade w1ll not drop out of the handle during use and will in fact become more securely wedged in the handle as the handle is pushed on to the blade during use. However, the blade'may be removed from the handle when desired, as for renewal if the bit is broken, and to accomplish this removal it is but necessary to grip the blade in a vise or other clampmg means and then pull the handle oft' the blade. As between the handle and blade, the handle is the most expensive part of the screw driver and with the present arrangement should a blade be broken its portion remaining in the handle may be removed therefrom as above described and a new blade -mav be substituted.

In addition to being held against casual movement out of the handle, the bla-de is by means above described held against turning movement relative to the handle. result is brought about by the fact, or results from the fact that the inner portion or end of the blade presents fiat surfaces to the side walls of the slot or kerf 29, and to-the fact that the inner end portion of the blade is of such dimensions that it may not turn in the kerf or slot.

The outer surface. of the ha'ndle 20 may be molded with any desiredydesign, and as here shown is smooth and rounded on its palm engaging end 37, and for a portion of its length is providedwith grooves or flutes 38 while toward its inner end it is reduced to provide a neck portion39 and then slightly enlarged and exteriorly roughened or knurled or ornamented as at 40.

The construction disclosed in Figs. 7, 8 and 9 is very similar to that shown in Figs. 1 through 6, and the screw driver shown in Figs. 7, 8 and 9 includes the same handle construction 20 and the same blade 22. The in- This last serts of the'respective constructions are, however, slightly diierent and the insert of Figs. 7, 8 and 9 is generall designated 41. This insert 41 includes an e ongated body portion 42 somewhat enlarged at its outer end 43 and this end43/ is provided with flat sides to be en'gaged by a wrench or other turning tool. A recess or passage 44 is formed centrally of the insert 41 and extends longitudinally therethrough from the outer end thereof substantially to the inner end thereof and terminates at the shoulders 45.

At its inner end the insert is milled or otherwise cut to provide a transversely extending kerf or slot 46 entering the recess 44 and of less width than the recess whereby the shoulders are formed. When the inner end of the insert is milled or otherwise cut to provide the slot 46, a pair of extensions or lingers 47 result and these extensions or fingers correspond with the extensions or fingers 30 of the form of the invention first described. On their outer edges or sides the extensions or fingers 47 are preferably tapered as shown at 48 and these fingers or extensions as disclosed in the figures now being considered are not bound with a collar or band.

It will be noted that the insert 41 is' provided with a washer 49 corresponding to the washer 33 of the other figures, this washer 49 may, however, be omitted as suggested in connection with the description of washer 33. From the foregoing description it will be apparent that the construction of Figs. 7 ,-8 and 9 differs from that of Figs. 1 through 6 essentially only in that provision for the collar 32 has not been made and the collar has been omitted. The insert 41 will be molded in the handle 20 as in the case of the structure previously described and the blade 22 may be inserted into and removed from the handle as will now be understood. Moreover, the blade will be held against accidentally moving out of the handle and against turning movement relative to the handle since the fiat tapered portions 36 of the blade will bind or wedge in the notch or kerf of the insertas will be understood.

In the form of the invention shown in Figs. 10. 11 and 12, the same, blade 22 is used together with the handle'20 although the insert generally designated 50 is of a construction different from that heretofore described. This insert includes an elongated body portion having its outer end portion 51 enlarged and provided with flat sides or surfaces to provide a nut adapted to be engaged by a wrench or other turning tool. A flange or washer-like portion 5 2 is provided integral with the nut or fiat sided portion 51, and takes the place of the separate or loose washer of the forms of the invention previously described. A loose' washer may, however, be used instead of the integral washer, the same as in the first forms ,e

and-opens through the portion 51 thereof and is adapted to receive a rtion of the shank 23 of the blade as will eunderstood. The inner end portionof the insert is flattened as at 54 whereby to flatten the portion' 55 of the recess, and at its extreme inner end the side walls'of the insert are pressed into engagement and preferably spot welded as at 56 closing the inner end of the insert.

'Ifhe extreme inner portion of the insert is deslgnated 58, and it will be noted that this portion is of greater width than the portion 54 of the insert, and that the portion 54 is greater in width than is the body of the insert. Since portions 54 and 58 of the insert are relatively flat it will be appreciated that when the insert is molded-into the handle there is no danger of the insert ever becoming loose in the handle in a manner either to permit relative turning movement between the handle and insert or in a manner to permit the insert 'to drop out of the handle.

It will be understood that the blade is lnsertable in and removable'from the insert 50,and thus the blade can be readily renewed as 1n the forms of the invention previously described. As clearly shown in Fig. 12 the tapered surfaces 36 of the inner end of the blade are received in the flattened portion of the recess of the insert whereby a wedging engagement may take place and whereby the blade will be held against turning movement in thehandle. Moreover, since the inner end, portions of the insert may be s ot welded as at 57 any possible spreading o the insert is prevented.

Figs. 13-and 14 show yet another modified structure and in these figures the handle is generally designated 59 and the blade 60. An insert 61 is molded in the handle as will be understood and this insert is provided with a longitudinally extending opening or recess 62 and on its outer surface intermediate its en ds comprises a smooth round portion 63. This insert also includes end portlons 64 and 65 which end portions are formed with angularly disposed or flat sides, and while the entire portion 65 is enclosed by the handle, but a part ofthe portion 64 is so enclosed, and

the remaining part extending inwardly of the c molded handle 59 provides a nut-like portion to be engaged by a wrench or the like.

Since the portions 64 and 65 include angularly disposed faces or, that is, are non-circular in cross-section, it will be apparent that the"- insert 61 will not be turnable in the handle. Toward its inner end one wall of the insert is provided with a transverse recess providing a flat or non-circular wall 66 on a thicker wall portion at the inner end of recess 62, and material of the handle indicated at 67 entering the transverse recess serves to further lock the insert in the handle.

The blade 60 at its inner end has a portion cut away whereby to provide an inclined or tapered flat face 68, and when the blade is inserted into the handle this inclined or tapered iiat face is adapted to wedge against the wall 66 of the insert in a manner to prevent casual separation of thehandle and blade, and in a manner to prevent turning movement of the blade in the handle. The taper or inclination of wall 68 is small, it preferably bein inclined only about one-half degree to t e axis of the blade. As a further means for preventing: this relative turning movement, the insert is provided in one side wall with a longi-,ff tudinal extending keyway 69 adapted to receive a longitudinal extending key 70 formed on the shank of the blade. This key may ge formed by pinching the shank between ies.

A further modified form of the invention is shown in Figs. 15 through 17, the construction of screw driver shown in these figures being somewhat similar to that shown in Figs. 13 and 14. In these Figures (15, 16 and 17) the handle is generally indicated 71, the blade 72 and the insert 73. Blade 72 is similar to the blade 60 of Fig. 13 but does not include a longitudinally extending key portion. However, at its inner end the blade 72 is cut away to provide a fiat tapered wall 74, similar to the surface 68 on blade 60.

Insert 73 is in construction the same as the inner end portion 65 of the insert 61, and has angularly disposed outer walls, that is hexagonal or non-circular, whereby the insert may bel tightly molded in the handle. The insert includes a longitudinally extending recess 75 opening through one end thereof in line with an opening 76 through the inner end of the handle and through which the shank of the blade may be inserted. One side wall of the insert has a. transverse recess the same as the insert 61 to provide a fiat or non-circular surface 77 in line with the recess 75 and some of the material of the handle may enter the transverse recess as shown at 78 to assist in locking the insert in the handle.

The blade 72 is inscrtable into and removable from the handle in the manner described in connection with the other figures of thc drawing and the tapered wall 74 at the inner end portion of the blade is adapted to wedgingly engage the inner surface 77 of the insert whereby the handle and blade will be held against casual separation. This same connection will serve to prevent turning movement of the handle on the blade. It will be noted that the insert 73 is relatively small andv does not include any portion extending beyond the handle and adapted to be gripped by a turning tool, as a wrench, and in this connection it will be understood that the construction of Figs. 15, 16 and 17 is particularly adaptable in small screw drivers.

From the foregoing description, it will be seen that in each form of the invention the handle is of moldable material and that in the respective disclosed structures the insert is in every instance molded into the handle in such a maner that turning movement of the handle on the insert is eii'ectively prevented. Further, it will be noted that the handles may or mav not, as desired, be made of insulating material and that in each instance the blade is not only secured in the handle against turning movement relative to the handle, but is secured in such a manner that casual separation of the handle and blade will not take place although the blade may be held as in a vise or the like and the handle pulled oil the blade. Additionally in connection with each of the figures of the drawings it should be borne in mind that the tapers on the inner ends of the blade Shanks are in each case exaggerated in order that the drawings will clearly show that such portions of the blade are tapered. In actual practice this taper is extremely slight. It will be evident that this construction in addition to permitting the ready renewal of a blade should it become broken. also permits the use of the same handle with different sizes of blades. Thus any number of blades of diiierent lengths and diiierent sizes of bits can be used in the same handle provided the inner ends of the shanks are of a size and shape to fit this handle, and therefore, for a kit including a number of different lengths and sizes of blades only one handle need be carried.

Having thus set forth the nature of our invention, what we claim is:

1. A screw driver comprising a handle and a blade, a metal -insert in said handle, said insert comprising an elongated member having a recess opening through the outer end thereof and receiving a portion of the blade, said insert having a transverse kerf across its inner end providing plane surfaces at the inner end of the recess, means to prevent lateral yielding ofthe walls of the kerf, and said blade being flattened at its inner end and tapered to enter the kerf to cooperate with the walls thereof to secure the handle and blade against casual separation and permit p ing a recess opening through the outer end thereof and receiving a portion of the blade, said insert having a transverse kerf across its inner, end roviding plane surfaces at the inner end of t e recess, said blade having its v inner end tapered and flattened and entering and cooperating with the walls of the kerf to normally secure the handle and blade against casual separation but to permit the blade to be withdrawn from the handle, and a metal collar about the kerfed end of theinsert to prevent spreading thereof.

3. A screw driver comprlsin a handle and a blade, a metal insert 1n sai handle, said' insert comprising an elongated member having a recess opening through the outer end thereof and receiving a portion of the blade, said insert having space opposed plane surfaces at the inner end of the recess, and said blade being flattened at its inner end and tapered to enter between the plane surfaces to frictionally cooperate therewith to secure the handle and blade against casual separation and permit the blade to be withdrawn from the handle. f 4. A screw driver includin a handle and a blade, a metal insert in said handle said handle formed of moldable material and having said insert molded therein sothat it is closely surrounded by said materialfor subi stantially its entire len h within the handle to prevent lateral yiel g of the inserty and hold it against turning in the handle, said insert provided with a longitudinal passage opening through the outer end thereof and having spaced opposed plane surfaces at the. inner end thereof, and said blade being fiattened at its inner end to enter between said plane surfaces to frictionally coo rate therewith to secure the handle and b ade against casual separation'and to permit the blade to be withdrawn from the handle.

5. A screw driver comprisin a handle and a blade, a metal insert 1n sai handle, said insert comprising an elongated member having a recess opening through the outer end thereof and receiving a portion of the blade, said insert havin a transverse kerf across its inner end provi ing plane surfaces at the inner end of the recess, means to prevent lateral yielding of thewalls of the kerf, and said blade being flattened 'at its inner end to enter the kerf to cooperate with the walls thereof to secure the handle and blade against casual separation and permit the blade to be withdrawn from the handle.

testimony whereof we ax our signatures HARRY B. CURTIS.

ARTHUR E. KEATING. 

